A：单细胞生物仅由一个细胞构成，对外界刺激不能产生反应
B：细胞的分裂和生长不受温度、营养条件的限制
C：组织的形成是细胞分化的结果
D：构成同一组织的细胞形态相似、结构不同
—I didn't hear you come in just now.
—That's good. We tried __________ any noise, for you were sleeping.
